Control apparatus



July 28, 1942. R. E. GOSSETT CONTROL APPARATUS Filed May 31, 1940 VACUUM TUBE AMPLIFIER ll E T TO ELECTRODE.

VACUUM TUBE AMP LIFWER INVENTOR BY dZ Patented July 28, 1942 CONTROLAPPARATUS Robert E. Gossett, Bellerose, N. Y., assignor to J. 0. RossEngineering Corporation, New York, N. Y., a corporation of New YorkApplication May 31, 1940, Serial No. 338,032

Claims.

This invention relates to control apparatus and more especially toapparatus for controlling the flow of fluid fuel to the burners of abattery of fluid fuel furnaces.

Heretofore, it has been customary to provide for each burner a devicewhich, in the event of flame failure at said burner, automatically shutsoff the supply of fuel to the entire battery of furnaces. As such deviceis quite expensive, the cost of installing control apparatus for abattery of furnaces has been undesirably high.

An object of this invention is control apparatus in which a singledevice of the type above referred to is caused to shut off the fuelsupply for a plurality of burners upon flame failure with respect to anyone of the burners.

In one form of apparatus embodying the invention, an electrical deviceresponsive to current variations is provided for actuating the main fuelvalve and is connected to each of a plurality of contacts normallybiased away from co-operating contacts, each of which is connected to anelectrode in a burner flame which constitutes part of the operatingcircuit for the device. ing the pairs of contacts in such manner that atleast one pair of contacts is always closed so that as long as eachburner is functioning properly there will be a steady flow of current tothe fuel valve control device to maintain the 7 supply of fuel to theburners. However, should there be flame failure at any one of theburners, then when the pair of contacts corresponding thereto areclosed, there will be an interruption in the current flow to theelectrical control dei vice which will then operate to shut off the mainvalve through which fuel is supplied to all the burners. Thus, oneinstrument is made responsive to flame failure in any one of a pluralityof burners and the use of an instrument for each burner is obviated,thereby very materially reducing installation costs.

Other objects, novel features and advantages of this invention willbecome apparent from the following specification and accompanyingdrawing, wherein:

Fig. 1 isa schematic View of an apparatus embodying the invention;

Fig. 2 is an elevation of a contact operating means;

Fig. 3 is a perspective view partially diagrammatic of a series ofcontact operating members, and

Fig. 4 schematically illustrates a modification.

Means are provided for successively 0105- :3

Referring now toFigs. 1, 2 and 3, a battery of heaters or furnaces H,l2, I3, Hi, If) and [6 are provided with fluid fuel burners IT, I8, 19,20, 2| and 2-2 which are supplied with fuel through a main supply pipe23 and provided with a selfclosing valve 24 equipped with an operatingsolenoid 25 effective when energized to hold the valve open. The burnersare provided with pilots 26, 21, 28, 29, 3B and 3| to which fuel issupplied by the branch pipe 32 connected to the main supply pipe 23provided with a self-closing valve 24a equipped with an operatingsolenoid 25a. Arranged in the burner flames are electrodes'33, 34, 35,36, 31 and 38 electrically connected to the stationary contacts 39, it,4!, 42, 43 and 44. Associated with the stationary contacts are themovable contacts 45, 56, 57, 48, 49 and 50, each of which is biased awayfrom the corresponding stationary contact by a spring 5|. Each of thestationary contacts is carried by a fixed arm 52 while each movablecontact is carried by a pivoted arm 53 on-which the spring 5| exerts adownward pull. Each arm 53 is provided with a cam follower 54 whichengages the corresponding one of cams 55, 56, 51; 58, 59, supported bythe shaft 6! driven by motor 62.

A vacuum tube amplifier 64 enclosed by a metal casing has the winding ofrelay 65 included in its output circuit and is provided with a terminal66 to which the contacts 45 to 59 are connected in parallel. Alternatingcurrent is supplied to the amplifier by the line 6'! and the casing ofthe amplifier is connected to the pipe 23 by a suitable conductor 63.The armature B8 of the relay 55 is connected to one wire of the supplyline 5'! and is adapted to engage two contacts 69 and it when the relayis energized and to automatically move out of engagement therewith whenthe relay 65 is de-energized. The contact 59 is connected through onepair of contacts ll of a two-pole single throw push button switch 12 toone terminal of the solenoid. 25 and is connected directly to oneterminal of the solenoid 25a while the contact 19 is connected throughthe energizing circuit of the motor 62 to the remaining wire of thesupply line 61. The remaining terminals of the solenoid 25 and 25a areconnected to the same wire of the supply line 61 as is the motor 62. Thesecond pair of contacts '53 of the switch 72 is included in a circuitwith the solenoid 25a between the wires of the supply line 6'5. Theswitch 12 is of such design that when one pair of contacts is closed,the other pair is opened and resilient means (not shown) are providedfor normally maintaining the switch in position to close the contacts H,

thereby closing the circuit through the solenoid 25. The design of theamplifier 64 is such that so long as a closed circuit exists between theterminal 66 and the amplifier casing through a burner flame, electrodeand corresponding pair of contacts, the relay 65 is energized to holdthe armature 68 to engage the contacts 69 and 16 but when an opencircuit results from flame failure, the relay 65 is de-energized, thuscausing the armature 66 to disengage both the contact 69 and the contact16. The particular structure of the above-described amplifier (shownschematically) in no part of the present invention and such a device,obtainable on the open market, has heretofore been used in such a way asto be influenced by a single burner only.

Under normal operating conditions, the valves 24 and 24a are held opendue to energization of the solenoids 25 and 25a. and fuel is supplied tothe burners through the main supply pipe 23 and to the pilots throughthe branch line 32 and each electrode contacts a burner flame. The camshaft 6I is rotated at a uniform predetermined speed by the motor 62 andpairs of contacts are successively closed by the cams, the cams being soconstructed that there is a slight overlap between the opening of onepair of contacts and the closing of the next pair so that at least onepair of contacts is always closed and there are periods during whichonly one pair of contacts is closed. Under these circumstances, there isa steady fiow of current between the terminal 66 and the amplifiercasing with the result that the armature 68 is held in engagement withthe contacts 69 and 16. Should a flame failure occur at any one of theburners, an open circuit will occur between the terminal 66 and theamplifier casing, when next the pair of contacts corresponding to suchburner is closed. Thereupon, the relay 65 will be de-energized and thearmature 68 will move away from the contacts 69 and 16 to opencircuitthe motor and open the circuits through the solenoids 25 and 25a withresulting closure of the valves 24 and 24a, to stop flow of fuel to allthe burners. Opening of the motor circuit results in immediate stoppageof the shaft 6I due to inertia and the fact that the shaft is driven bythe motor at low speed. After the cause of the flame failure has beendetermined and remedied, the apparatus may be manually returned to itsoriginal condition and operation resumed. In putting the apparatus incondition for operation, the switch 12 is actuated to open the contactsH and close the contacts 13, thereby closing a circuit through thesolenoid 25a to energize it and effect opening of the valve 24a. Uponopening of the valve 24a, fuel fiOWs through the pipe 32 to the variouspilots which are manually lighted. After all the pilots have beenlighted and the electrodes have warmed up sufficiently to cause flow ofcurrent through the amplifier circuit, thereby energizing the relay 65to bring the armature 68 into engagement with the contacts 69 and 16,the switch 12 is released to close the contacts 1| thereby causingcurrent flow through the solenoid 25 to energize it and open the valve24 to permit the flow of fuel to the main burners.

In Fig. 4, the vacuum tube amplifier I64 enclosed by a metal casing, hasthe wiring of a relay I65 included in its output circuit and is providedwith a terminal 66 to which the aforementioned contacts 45 to 56 areconnected in parallel. Alternating current is supplied to the amplifierby the line 61 and the casing of the amplifier is connected to the pipe23 by a suitable conductor 63. The armature I68 of the relay I65 isadapted to engage either of two contacts I69 and I10 and is connected toone wire of the line 61. The two contacts I69 and I16 are respectivelyconnected through the windings of actuating solenoids I25 and I25a andthrough the energizing circuit of the motor 62 to the remaining wire ofthe supply line. The valves I24 and I24a are of the selfopening type andthe solenoids I25 and I25a are effective upon energization to close suchvalves. The design of the amplifier I64 is such that so long as a closedcircuit exists between the terminal 66 and the amplifier casing througha burner flame, electrode and corresponding pair of contacts, the relayI65 is energized to hold the armature 68 against the contact 16 but whensuch circuit is broken by flame failure, the relay is de-energized, thuscausing the armature I68 to disengage the contact I16 and engage thecontact I69.

Under normal operating conditions for this modification, the valves I24and I24a are open and fuel is supplied to the burners as previouslydescribed. The cam shaft is rotated also as previously described withresultant successive closure of the pairs of contacts with a slightoverlap between the closure of successive pairs. Under thesecircumstances, there is a steady flow of current between the terminal 66and the amplifier casing with the result that the armature I69 is heldin engagement with the contact I16. Should flame failure occur at anyone of the burners,

' an open circuit occurs between the terminal 66 and the amplifiercasing when next the pair of contacts corresponding to such burner isclosed. Thereupon, the relay I65 is de-energized and the armature I66moves away from the contact I16 to open circuit the motor and moves intoengagement with the contacts I69 to close the circuits through thesolenoids I25 anl I25a with resulting closure of the valves I24 and I24ato stop flow of fuel to all the burners. To facilitate putting theapparatus in condition for operation, a by-pass I1I may be providedaround the valve I24a, this by-pass being provided with a manuallyoperable valve I12.

In the event of the invention being embodied in a structure wherein theinertia is insufficient to stop the rotation of the cam shaft within thearc allotted to each pair of contacts suitable brake mechanism may beused. Such brake mechanism may be of any structure which will effect thestopping of the cam shaft within the allotted arc and may be energizedin any suitable manner upon breaking of the circuit between the terminal66 and the amplifier casing.

If it is desired to use such apparatus for less than six burners, one ormore of the electrodes may be connected to two or more of the stationarycontacts. Thus, an apparatus designed for use with six furnaces may beconverted to an apparatus for use with a lesser number of furnaces.

This application is a continuation in part of applicants co-pendingapplication, Serial No 222,820.

I claim:

1. A device of the character described comprising a plurality ofburners, a common fuel supply pipe for said burners, a valve in saidpipe, an electrical valve-operating device, a normally open circuitleading to said device for each bumer in which circuit current flow isresponsive to fuel combustion at said burner, and means for closing saidcircuits successively and opening them after a predetermined period suchthat at least one circuit is always closed, said valve-operating devicebeing responsive to current flow through the closed circuit to maintainsaid valve open and to lack of current flow through the closed circuitto close said valve.

2. Apparatus of the character described comprising a plurality ofburners, means for supplying fuel to said burners, a normally open valvecontrolling said fuel supply means, a circuit for each burnercharacterized by havin current flow therein responsive to fuelcombustion at the associated burner, an electrical valve-operatingdevice and means for connecting said circuits successively with saiddevice and disconnecting said circuits therefrom at the end of apredetermined period such that at least one circuit is always closed,said device being responsive to current flow through a connected circuitto maintain said Valve open and to lack of' current flow through aconnected circuit to close said valve.

3. Apparatus of the character described coil prising a plurality ofburners, means for supplying fuel to said burners, a valve controllingsaid fuel supply means, a circuit for each burner characterized byhaving current iiow therethrough responsive to fuel combustion at theassociated burner, an electrical valve-operating device common to saidcircuits, a switch for each circuit, and means for closing said switchessuccessively and opening each switch after a predetermined period suchthat at least one pair of contacts is always closed, said device being rsponsive to current flow through a closed switch to maintain said valveopen and to lack of current flow through a closed switch to close saidvalve.

4. Apparatus of the character described comprising a plurality ofburners, a plurality of circuits in each of which current flow isresponsive to fuel combustion at one of said burners, a currentresponsive device common to said circuits for controlling fuel supply tosaid burners, a switch for each circuit, and means for closing saidswitches successively and opening each switch at the end of apredetermined period such that at least one switch is always closed.

5. Apparatus of the character described comprising a plurality ofburners, a plurality of circuits in each of which current flow isresponsive to fuel combustion at one of said burners, a currentresponsive device common to said circuits for controlling fuel supply tosaid burners, a switch for each circuit, means including rotating cammembers for successively closing said switches and opening each switchat the end of a predetermined period such that at least one switch isalways closed, and means for rotating said cam members.

6. In a multiple heater system having a plurality of burners eachassociated with a combustion chamber, the combination of a commongoverning means for stopping the operation of all of said burners, asensing device associated with each of said combustion chambers and eachoperable to detect flame failure in the combustion chamber with which itis associated, and means operable to place said sending devicessuccessively in sole control of said governing means.

7. In a multiple heater system having a plurality of burners eachassociated with a combustion chamber, the combination of a commongoverning means for stopping the operation of all of said burners, and asensing device associated with each of said combustion chambers and eachoperable to detect flame failure in the combustion chamber with which itis associated, individual detector circuits for each of said sensingdevices, means operable through association with any one of saiddetector devices to control said common governing means in accordancewith the combustion conditions sensed by the sensing device of suchdetector circuit, and a progressive detector switch operable toassociate said detector circuits with said common governing means inpredetermined timed succession.

8. In a multiple heater system having a plurality of burners eachassociated with a combustion chamber, the combination of a commongoverning means for stopping the operation of all of said burners, and asensing device associated with each of said combustion chambers and eachoperable to detect flame failure in the combustion chamber with which itis associated, individual detector circuits for each of said sensingdevices, means operable through association with any one of saiddetector devices to control said common governing means in accordancewith the combustion conditions sensed by the sensing device of suchdetector circuit, and a progressive detector switch operable toassociate said detector circuits with said common governing means inpredetermined timed succession, said switch being operable to place eachsucceeding detector circuit in association with said common means justprior to the disassociation of the preceding circuit.

9. A device of the character described comprising a plurality ofburners, a common fuel supply pipe for said burners, a valve in saidpipe, an electrode adapted to contact each burner flame, an electricvalve-operating device, a plurality of circuits each including oneelectrode and said electrical valve-operating device, and means forclosin said circuits successively and opening them after a predeterminedperiod such that at least one circuit is aiways closed, said electricalvalve-operating device being responsive to current flow through a closedcircuit to maintain said valve open and to lack of current flow througha closed circuit to close said valve.

10. A device of the character described comprising a plurality ofburners, a common fuel supply for said burners, a valve controlling saidfuel supply, electrical valve-operating device, a normally open circuitleading to said evice for each burner in which circuit cur ent flow isresponsive to fuel combustion at said burner, and means for closing saidcircuits successively and opening them after a predetermined period suchthat at least one circuit is always closed, said valve-operating devicebeing responsive to current flow through a closed circuit to maintainsaid valve open and to lack of current flow through a closed circuit toclose said valve.

11. Apparatus of the character described comprising a plurality ofburners, a circuit for each burner characterized by having current flowtherein responsive to fuel combustion at the associated burner,electrically-operated means for controlling fuel supply to said burners,and means for connecting said circuits successively with said fuelcontrol means and disconnecting said circuits therefrom after apredetermined period such that at least one circuit is always connectedto said fuel control means, said latter means being responsive tocurrent flow through a closed circuit to maintain said valve open and tolack of current flow through a closed circuit to close said valve 12. Ina multiple heater system having a plurality of burners, the combinationof a governing means for stopping the operation of all of said burners,and a sensing device associated with each burner and each operable todetect flame failure at the burner with which it is associated,individual detector circuits for each of said sensing devices, meansoperable through association with any of said detector circuits tocontrol said governing means in accordance with the combustionconditions sensed by the sensing device of such detector circuit, and aprogressive detector switch operable to associate said detector circuitswith said governing means in predetermined time succession.

13. A device of the character described comprising a plurality of fuelburners, an electrode adapted to contact with each burner flame, anelectrical fuel control device, and means for electrically connectingsaid electrodes successively to said control device and disconnectingthem from said control device after a predetermined period such that atleast one electrode is always connected to said device, said devicebeing responsive to current flow through said connecting means tomaintain fuel flow to said burners and to lack of current flow throughsaid connecting means to interrupt fuel flow to said burners.

14. In a multiple burner system having a plurality of individualburners, common control means for stopping the operation of all of saidburners, a plurality of safety control devices one associated with andresponsive to each of said burners, and means operable to place saidsafety control devices in sole governing control of said common controlmeans in predetermined timed succession.

15. In a multiple burner control system, a plurality of detectorelements adapted for operative individual association with theindividual burners of a multiple burner system, a main control mechanismadapted for controlling association with all of the burners of such amultiple burner system, and a means utilizing said detector elements inpredetermined timed succession to produce a control impulse thecontinuity of which governs said main control mechanism.

16. In a multiple burner control system, a plurality of detectorelements adapted for operative individual association with theindividual burners of a multiple burner system, a main control mechanismadapted for controlling association with all of the burners of such amultiple burner system, and a means operable to connect said detectorelements operatively to said main control mechanism in predeterminedtime succession.

17. In a multiple heater system having a plurality of burners, thecombination of a common governing means for stopping the operation ofall of said burners, a sensing device associated with each burner andeach operable to detect flame failure at the burner with which it isassociated, and means operable to place said sensing devicessuccessively in sole control of said governing means.

18. In a multiple heater system having a plurality of burners, thecombination of a common governing means for stopping the operation ofall of said burners, and a sensing device associated with each burnerand each operable to detect flame failure at the burner with which it isassociated, individual detector circuits for each of said sensingdevices, means operable through association with any one of saiddetector devices to control said common governing means in accordancewith the combustion conditions sensed by the sensing device of suchdetector circuit, and a progressive detector switch operable toassociate said detector circuits with said common governing means inpredetermined timed succession.

19. In a multiple heater system having a plurality of burners, thecombination of a common governing means for stopping the operation ofall of said burners, and a sensing device associated with each burnerand each operable to detect flame failure at the burner with which it isassociated, individual detector circuits for each of said sensingdevices, means operable through association with any one of saiddetector devices to control said common governing means in accordancewith the combustion conditions sensed by the sensing device of suchdetector circuit, and a progressive detector switch operable toassociate said detector circuits with said common governing means inpredetermined timed succession, said switch being operable to place eachsucceeding detector circuit in association with said common means justprior to the disassociation of the preceding circuit.

20. In a multiple heater system having a plurality of burners, thecombination of a governing means, and a sensing device associated witheach burner and each operable to detect flame failure at the burner withwhich it is associated, individual detector circuits for each of saidsensing devices, means operable through association with any one of saiddetector devices to control said governing means in accordance with thecombustion conditions sensed by the sensing device of such detectorcircuit, and a progressive detector switch operable to associate saiddetector circuits with said common governing means in predeterminedtimed succession.

ROBERT E. GOSSE'I'I'.

